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大肠菌群寄居于人和其他温血动物的肠道之中，是其粪便中的主要细菌，应用大肠菌群作为饮用水的卫生质量和是否受粪便污染的指示生物，已有较长历史。目前已逐渐建立起一整套比较成熟的确定样品中大肠菌群密度的方法，这些方法已公认为对不同用途水的卫生质量进行细菌学检验的标准方法( A. P. H. A., A. W.W. A. & W. P. C. F，1971)。
大量调查研究结果表明，生活污水中存在着数量惊人的肠道类细菌。这些肠道类细菌随污水进入海洋后，由于环境条件的骤然改变，以及海洋微生物的拮抗作用和抗菌素的产生，它们会在短时间内大量死亡(Jones, 1971; Lessard & Sieburth, 1983；钱振儒、张景镛，1985a, 1985b)。然而，仍有一定数量的肠道类细菌能在海水里存活一段时间，特别是在有机物质含量丰富的污染海水中，其存活时间更长些(薛廷耀，1962)。
所以，在海洋环境污染的监测和评价中，尤其对河口近岸水域以及养殖水体、海水浴场的污染监测和评价时，把海水的大肠菌群密度作为一项监测和评价项目，不仅是可能的，而且也是必要的。为此，世界多数国家己作了明确规定，一般海水每升水样中大肠菌群数不得超过10000个(此标准也适用于与人体直接接触的浴场海水)，而养殖水体则每升不得超过700个。我国也作了同样的规定。但是在我国海洋环境污染监测和评价的实际工作中，运用生物监测手段的工作，包括大肠菌群的监测，不仅做得不多，而且尚未受到普遍重视。
本文是1984年海河口区有机污染现状调查和评价中有关大肠菌群数量分布及其与水域有机污染程度相关分析的总结，试图通过海河口区这一典型实例，来论证大肠菌群作为河口海域有机污染的指示生物是完全可行的。 相似文献
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《Marine Policy》2015
There is a need for effective mechanisms to be in place in order to allocate fishing possibilities. This seems crucial so that distributional concerns regarding this issue are properly addressed. This paper aims at providing insights into the allocation of fishing possibilities from Basque fisheries. We put forward this case in terms of its outcomes to the incentives deployed by the allocation system. The institutional substratum plays a key role in the outcomes of the system. In fact, the fishermen's traditional collective approach predominates even though the management system tends towards individual rights allocation and promotion of rights transferability. This is particularly notable in the case of inshore Basque fisheries. 相似文献
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本文以世界海域头足类的28个科及其重要种类的分布为依据,结合生境、生态和捕获状况,探讨了头足类的分布特点、分布趋向和区系特征。 相似文献
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Paul Loubere Brittani JacobsenDorthe Klitgaard Kristensen Katrine Husum 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(5):535-545
Benthic foraminiferal shell geochemistry has been extensively used to develop paleoceanographic tracers. Many of these proxies are sensitive to the geochemical conditions of the microhabitats selected by particular foraminiferal species. Understanding these microhabitats, then, is essential for proper interpretation of the proxies. A simple, broadly accepted, view is that foraminiferal species’ habitats are vertically stratified in the sediments due to general pore-water chemical gradients, which develop in response to the seabed organic carbon flux. Species are categorized into epifaunal, shallow infaunal and deep infaunal habitats, and are supposed to acquire the geochemical characteristics of these. However, this view is at odds with species’ distributional data and foraminiferal geochemical properties. We present an alternate model in which foraminifera select for habitats within the bio-irrigation system of the sediments created by the activities of macro-/meio-fauna. Our distributional and geochemical data indicate that foraminiferal species seek particular biotic associations and geochemical conditions within the complex bio-architecture of the sediments and are not tied to particular sediment depths, or the general pore-water chemistry of their apparent habitation zone. Instead, foraminifera inhabit micro-environments with steep oxic to anoxic gradients. This might account for disparities among geochemical tracers. 相似文献
6.
《Marine Policy》2001,25(2):103-112
Rights-based management regimes are considered by economists as an important solution to the problems of excess capacity and biological over-harvesting of fisheries. In practice, adoption of such regimes, and particularly of those relying on individual quota allocations, has often met with resistance from within the fisheries concerned. A key reason for this resistance appears to be the distributional conflicts which arise in the process of implementing the regimes. An economic analysis of the nature of these conflicts in the different contexts in which they have been observed is proposed. The approach centres on the way in which distributional conflicts can influence the operation of management systems and their impacts on fisheries, from the country to the individual firm level. As an illustration, an analysis of the economic processes at firm level is developed based on the simulation of a fishery managed under individual transferable quotas. 相似文献
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《African Journal of Marine Science》2013,35(1):397-417
Groundfish surveys carried out between October 1992 and October 1996 were used to describe the demersal assemblages of the northern Benguela along the Namibian coast. Multivariate analyses indicated a clear separation between shelf and slope habitats, which were divided into three and two assemblages respectively. These divisions were distinct, with clear distributional boundaries separating them. Species determining the structure of these divisions and subdivisions and their relative abundances were identified. Depth, bottom temperature, bottom salinity and dissolved oxygen were all significantly correlated with the spatial distribution of the assemblages. Minor changes or shifts in the distribution of assemblages were observed over the study period, although patterns of species associations remained relatively constant. 相似文献
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Ｔｈｅｖａｒｉａｔｉｏｎｐａｔｔｅｒｎｓａｎｄｃｏｒｒｅｌａｔｉｏｎｓｏｆｔｏｔａｌｐｈｏｓｐｈｏｒｕｓ,ｏｒｇａｎｉｃｐｈｏｓｐｈｏｒｕｓａｎｄｐｈｏｓｐｈａｔｅｉｎｔｈｅＣｈａｎｇｊｉａｎｇＥｓｔｕａｒｙ￥ＨｕａｎｇＺｉｑｉａｎｇａｎｄＪｉＷｅｉ... 相似文献
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W. Armonies 《Journal of Sea Research》1996,35(4):323-334
The large-scale (km) distributional patterns of juvenile bivalves are established by larval settlement and subsequently changed due to actively initiated postlarval migrations (byssus-drifting), resuspension during sediment disturbance, and local differences in mortality. Repeated mapping of 0-group bivalve distribution during two summers was combined with simultaneous registrations of the numbers of drifting specimens. Species differed in their susceptibility to passive resuspension and their activity in byssus-drifting, but the two ways of entry into the water column were independent of each other. As a result, the relative magnitude of byssus-drifting and passive resuspension varied with the species. While hydrographical conditions always determined the changes in the distributional patterns of passively eroded species, this was not the case in active migrations of byssus-drifting bivalves. A comparison of the distributional patterns of juveniles over two consecutive years showed similar patterns in the tellinid clam Macoma balthica and the razor clam Ensis americanus. In these two species spatfall mainly occurred around mean low-tide level. Subsequently, juvenile M. balthica rapidly accumulated in the upper intertidal, whereas juvenile E. americanus accumulated subtidally. In mussels Mytilus edulis the distribution of juveniles only changed in a longshore direction, not in the tidal level occupied. The spatial pattern of cockles Cerastoderma edule changed from aggregation of the early spat in the mid and lower intertidal towards a more uniform distribution of recruits over these tidal flats. There were only a few patches of high abundance left at the end of summer. Finally, in juvenile clams Mya arenaria the spatial patterns of both spatfall and redistribution were unpredictable.On a km-scale, abundance of some species correlated with sediment granulometry. Presumably, this does not reflect a causal relationship but is a consequence of the correlation between grain size distribution and tidal level within the area studied. On a scale of hundreds of metres, there were no consistent correlations between juvenile abundance and sediment granulometry in any species. In summary, it seems that hydrography ruled the initial settlement of larvae to the sediment and strongly influenced the subsequent redistribution of juveniles caused by passive resuspension. The outcome of actively initiated migrations, on the other hand, was only weakly influenced by hydrography. Therefore it is suggested that hydrography plays a dominant role in the initial development of km-scale distributional patterns of just-settled bivalves in the Wadden Sea, while habitat selection is delayed to the byssus-drifting postlarvae phase. 相似文献
10.
The effect of directionality on extreme wave design criteria 总被引：1，自引：0，他引：1
Sea state design criteria for offshore facilities are frequently provided by direction. For example, it is typical for return-period values of the significant wave height to be specified for each of eight 45° sectors in addition to the omni-directional case. However, it is important that these criteria be consistent so that the probability of exceedance of a given wave height from any direction derived from the directional values is the same as for the omni-directional value. As recently demonstrated by Forristall it is not sufficient simply to scale the directional values so that the value of the wave height from the most severe sector is the same as the omni-directional value.We develop an approach for establishing appropriate directional criteria and an associated omni-directional criterion for a specific location. The inherent directionality of sea states is used to develop a model for the directional dependence of distributions of storm maxima. The directional model is applied to the GOMOS data, and the distributional properties of the 100-year significant wave height are estimated and the implications for design discussed. An objective risk-cost approach is proposed for optimising directional criteria, while preserving overall reliability. Simulation studies are performed, using realistic extreme value assumptions, to quantify the uncertainties. 相似文献
11.
为探究长蛇鲻(Saurida elongate)的生态习性和分布规律,并为长蛇鲻资源的合理利用与养护提供科学依据,本文根据2016年秋季在山东南部近海进行的渔业资源与环境调查数据,分析了该海域长蛇鲻的分布特征,研究长蛇鲻成体、幼体的分布差异,并利用广义可加模型(GAM)研究其分布与生物因子和环境因子的关系。结果表明,长蛇鲻成体与幼体的分布存在差异,成体分布范围广,幼体主要分布在30 m等深线及以浅水域。GAM模型的结果表明,饵料生物、底层水温、水深和底层盐度是影响长蛇鲻相对资源量分布的主要因子。成体、幼体的分布与影响因子的关系差异极显著(P<0.01)。长蛇鲻成体的相对资源量随饵料生物和底层水温的增加表现为先上升后下降的趋势,而幼体呈现一致上升趋势;成体和幼体的相对资源量随水深增加均呈下降趋势;幼体相对资源量随底层盐度增加有明显上升趋势,而盐度对成体的影响不显著。本研究认为山东南部近海是长蛇鲻的重要栖息地,水温和盐度是成体和幼体分布差异的可能原因。 相似文献
12.
为了解桑沟湾大型底栖动物多样性现状,作者于2009年7月和12月对桑沟湾9个站位进行2个航次的采样,以种类组成、生物量和栖息密度为基础,采用物种多样性指数(Shannon-Wiener index)、物种丰富度指数(Species richnessindex)以及物种均匀度指数(Species evenness index)对大型底栖动物多样性及其影响因子进行了分析。结果表明:共采到大型底栖动物83种,其中多毛类45种,占种类总数的54.22%,软体动物11种(占13.25%),甲壳类23种(占27.71%),其他4种(占4.82%)。各站获得平均种类数在2～28种之间,种类最少的出现在夏季的C8站,最多的出现在夏季的C4站。不同养殖区生物多样性指数差异也很大,物种多样性(H′)和物种丰富度指数(D)均以贝类养殖区最高,藻类养殖区最低,而物种均匀度指数(J′)以贝藻混养区最高,藻类养殖区最低。生物多样性除了受种的数量及其个体密度的影响外,还与多种环境因素有关,相关性分析结果表明:水温、盐度、沉积物类型和硫化物含量是影响桑沟湾大型底栖动物生物多样性的主要环境因子。 相似文献
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During the period August 1985 to May 1986, phytoplankton in the southern Taiwan Strait was collected and studied for distributional variability in relation to hydrography. The results indicated that maximum standing crops of phytoplankton occurred in October and May due to the outgrowth of certain species of diatoms and blue-green algae. The majority of phytoplankton appeared in the water in the top 25 m and occurred in distinct clusters under the influence of water movement. Multivariate analysis indicated that hydrographic parameters, which accounted for the variability of phytoplankton distribution, varied seasonally. Vertical, spatial and temporal variabilities were also apparent. The close relationship between hydrography and algal distribution justifies the use of variations in the phytoplankton population as a useful tracer of water movement. 相似文献
14.
This paper deals with the problem of coherent radar detection of targets embedded in clutter modeled as a compound-Gaussian process. We first provide a survey on clutter mitigation techniques with a particular emphasis on adaptive detection schemes ensuring the constant false-alarm rate (CFAR) property with respect to all of the clutter parameters. Thus, we propose a novel decision rule based on a recursive covariance estimator, which exploits the persymmetry property of the clutter covariance matrix. Remarkably, the devised receiver is fully CFAR in that its threshold can be set independently of the clutter distribution as well as of its covariance, even if the environment is highly heterogeneous; namely, the disturbance distributional parameters vary from cell to cell. At the analysis stage, we compare the performance of the novel detector with some classical radar receivers such as that of Kelly and the adaptive matched filter both in the presence of simulated as well as on real radar data, which statistical analysis has shown to be compatible with the compound-Gaussian model. The results show that the new receiving structure generally provides higher detection performance than the others and, for a fluctuating target, it uniformly outperforms the counterparts. We also provide a discussion on the CFAR behavior of the analyzed receivers as well as on their computational complexity. 相似文献
15.
Distributional characteristics of planktonic Amphipoda (Hyperiidea) in the South Huanghai Sea and East China Sea 总被引：1，自引：1，他引：1
Ｄｉｓｔｒｉｂｕｔｉｏｎａｌ ｃｈａｒａｃｔｅｒｉｓｔｉｃｓ ｏｆ ｐｌａｎｋｔｏｎｉｃ Ａｍｐｈｉｐｏｄａ（Ｈｙｐｅｒｉｉｄｅａ） ｉｎ ｔｈｅ Ｓｏｕｔｈ Ｈｕａｎｇｈａｉ Ｓｅａ ａｎｄ Ｅａｓｔ Ｃｈｉｎａ ＳｅａＬｉｎＪｉｎｇｈｏｎｇａｎｄ... 相似文献
16.
《Marine Policy》2016
The primary role of marine protected areas (MPAs) is marine conservation, however policy and practice around MPAs have not reflected this. The focus on cost-effectiveness by spatial conservation prioritization has led to a bias towards placing MPAs in areas that are least threatened. This study investigates how conservation priorities differ between two management strategies of either targeting or avoiding high threat areas for protection, using the case of the Sulu Sulawesi Seas in the Coral Triangle. For both strategies, the target of protecting 20% of habitat could not be achieved solely by protecting low threat areas. A high proportion of the region had large differences in conservation outcomes between the two strategies; majority of these areas were highly prioritized in the threat avoidance strategy but had low or zero importance in the threat selection strategy. Selecting for highly threatened areas required less habitat area to be protected to achieve the same conservation target and resulted in a more equitable distribution of priority sites per country and sub-region. This demonstrates the importance of deciding on the objectives of conservation and management policies up-front. The results suggest that, contrary to the common practice of avoiding threats in spatial planning, a threat selection strategy should be part of the management toolbox, particularly in transboundary planning for regions with high overall threat levels, where it may be important to achieve shared conservation targets equitably. 相似文献
17.
《Marine Policy》2014
This paper seeks to illustrate the role of principles in an emerging regime for the conservation and sustainable use of marine biodiversity in areas beyond national jurisdiction (ABNJ). While certainly not a standalone solution for a complex issue, principles nonetheless serve an essential function in regime-building, bridging legal and governance processes to identify new ways forward. Given the fundamental questions of international law at hand – the restriction of the freedoms of the high seas, the nature of UNCLOS as a “living instrument” and the need to engage in innovative practice spanning law and governance – it comes as no surprise that discussions on the future of ABNJ have been highly polarized. Principles offer points of convergence to address both the “regulatory gaps” and “implementation gaps” identified and serve the structural needs of both law and governance to produce dynamic change in the protection of marine biodiversity in ABNJ. Through their function as precursors to rules, principles prepare a common space for the emergence of a regime and give it a set of mechanisms through which it can strengthen its connections to the diversity of instruments and institutions involved in addressing a multifaceted problem. A statement of principles to strengthen the conservation and sustainable use of marine biodiversity in ABNJ – many of which constitute customary international law – would therefore be a logical and constructive next step in this on-going process. 相似文献
18.
渔业资源调查采样设计优化研究进展 总被引：3，自引：0，他引：3
渔业资源调查是指利用一定的采样设计,对渔业种群进行空间布点采样,以获取研究区域内鱼类时空分布以及生物学和生态学信息。但是大量的研究表明,不同的鱼类分布适合不同的采样设计,需要根据鱼类的分布特点和调查目标(种群丰度等)优化采样设计,保证数据的准确性和精度。近年来,相关的研究有很多,涉及不同采样设计的比较和应用以及影响数据质量因素的探究。作者着重介绍了定点采样、传统方法、适应性方法和基于地理统计学方法,叙述了计算机模拟及重采样技术在采样设计优化中的应用以及相对偏差、相对估计误差、设计效果和变异系数等评价采样设计性能的指标,同时对采样设计中需要注意的问题进行介绍,最后进行了总结并对未来的研究工作进行展望。 相似文献
19.
N. A. Timofeev 《Physical Oceanography》2009,19(2):85-95
We describe the in-line methods for processing the results of observations of the vertical distribution of wind speed with
an aim of evaluation of the parameters characterizing the stable state of the surface layer of the atmosphere and the roughness
of the sea surface. It is proposed to use these data for the interpretation of the results of satellite scatterometric measurements
of the surface wind speed in order to increase their accuracy. 相似文献
20.
Heather Tallis Phillip S. Levin Mary Ruckelshaus Sarah E. Lester Karen L. McLeod David L. Fluharty Benjamin S. Halpern 《Marine Policy》2010,34(2):340-348
Despite the widely accepted need for ecosystem-based management of coastal and marine systems, many managers struggle with how to put these principles into practice. Commonly voiced concerns include complicated and expensive implementation, prohibitive data requirements, and lack of testing with long-term applications. We address some of these perceived barriers by providing guidance on strategies and approaches that can be used for the steps of one ecosystem-based management process, the integrated ecosystem assessment framework, including scoping, defining indicators, setting thresholds, risk analysis, management strategy evaluation, monitoring and evaluation. Importantly, we demonstrate how an ecosystem-based management approach can be utilized in a variety of contexts which vary widely in data quality and availability, governance structure, and time frame. We then illustrate the suggested steps in the process by exploring two case studies that represent realistic ends of the data/governance/time frame spectrum: Puget Sound, Washington, USA and Raja Ampat, Indonesia. By providing concrete suggestions for how to move forward with key steps in an integrated management process, we show that ecosystem-based management is feasible from a range of starting points and that for any given starting point there are numerous productive paths forward. 相似文献